FM684894 Force DECAL, TOP FRONT

Fuel Injection Valves
Testing Fuel Injection Valves: Whenever an engine performs in such a manner that a fuel injection valve is suspected of causing trouble, test all fuel injection valves. To test the injection valves, loosen the fuel injection line nuts at the fuel injection pumps, one at a time, while the engine is running. When a nut is loosened and the exhaust smoking is completely or partially eliminated and the irregularity in running is not affected, this identifies the defective valve and a new one should be installed in that cylinder. These valves can be tested by your Caterpillar dealer.
LOOSEN FUEL INJECTION LINE NUT TO TEST VALVE
REMOVING FUEL INJECTION VALVE
1-Retainer nut. 2-Fuel injection valve nozzle assembly. 3-Plug. 4-Cover. Removing Fuel Injection Valves: Before removing a valve clean the dirt from around the valve and connections. If the engine is equipped with glow plug starting aids, the glow plug should first be removed before removing and replacing a fuel injection valve to eliminate the possibility of damaging the glow plug. See the topic GLOW PLUGS.Disconnect the fuel injection line from the injection valve and pump. Install the plug (3) and cover (4). Remove the valve retainer nut (1) and lift out the nozzle assembly (2) and body as a unit. Installing Fuel Injection Valves: Before installation of a fuel injection valve, be sure the wrench is clean. Put the dust cover on the valve body as soon as possible to prevent dirt entering the fuel passage. Install the fuel injection valve in the following manner:1. Screw the valve body 7 into the fuel injection valve nozzle assembly only finger tight. The threads of the body and nozzle assembly are made to fit loosely. The clearance between the threads provides a passage for fuel to enter the nozzle assembly from the body.2. Insert the nozzle assembly and valve body as a unit into the pre-combustion chamber opening. Turning the body in a clockwise direction and at the same time pressing down will assure alignment of the serrations.3. Install a new large seal (5) on the retainer nut. A light coating of lubricant on the seal will permit it to seat properly.4. Tighten the retainer nut to prevent leaks between the nozzle assembly and nozzle assembly seats. A torque of 100 to 110 pounds feet is adequate to tighten the retainer nut.
INSTALLING FUEL INJECTION VALVE
5-Large seal. 6-Small seal. 7-Injection valve body.5. Place a new small seal (6) over the threads on the top of the valve body and on the retainer nut.6. Connect the fuel injection line and tighten the nuts.Fuel Injection Pumps
Testing Fuel Injection Pumps: It is not usual for one pump on an engine to require replacement unless all the pumps are worn. Worn fuel injection pumps will result in loss of power and hard starting. When loss of power and hard starting is accompanied with a clear exhaust, good compression and no blow-by gases from the crankcase breather it indicates worn injection pumps. The tools and information required to service and check fuel injection pumps are available at your Caterpillar dealer.